Bisphenol A (BPA) is a chemical used in the manufacture of hard plastics which can be found in a wide range of products, including baby bottles, plastic utensiles, and plastic food containers. It has been the focus of some controversy over its safety, and the resulting debate reveals much about how the current system deals with such issues.

The concern is that BPA can leech from plastic containers into the food or liquid it contains, and when consumed can have negative health effects. The debate is over how to interpret existing evidence about BPA safety, which gives conflicting results. Essentially it is a debate about how to weight different kinds of evidence, and where safety thresholds should be.

The Science of Toxins

Toxicity is always a function of dose. Anything is toxic at high enough dose, and safe at a low enough dose. Regulatory agencies concerned with protecting the public health, therefore, typically use scientific evidence to establish doses that are likely to cause toxicity in humans and then set safe levels of exposure significantly below that level to create a buffer of safety. But what kind of evidence is used?

I know I should exercise regularly, but I’m congenitally lazy and am ingenious at coming up with excuses. There’s an exercise machine that sounds like the end of all excuses, a dream come true. You’ve probably seen the ads in various magazines. The ROM Machine: “Exercise in Exactly 4 Minutes per Day.” It claims that you can get the same benefit, at home, from 4 minutes a day on the ROM as you can from 20 to 45 minutes aerobic exercise plus 45 minutes weight training plus 20 minutes stretching at the gym. It allegedly balances blood sugar and repairs bad backs. It is for everyone from age 10 to over 100.

Does this sound too good to be true? That’s usually a clue that it is too good to be true. I was skeptical and I sent in for the company’s free DVD. There were more clues in the DVD. They had testimonials from 2 chiropractors, several trainers, and lots of satisfied users, but they didn’t have recommendations from a single medical doctor or scientist. In fact, they mentioned a couple of doctors who disputed their claims, including one cardiologist who told his patient that kind of strenuous exercise could kill him. To prove you could get a good workout from the machine, they put people on it, got them to huff and puff and sweat a lot, and then got them to say, “That was a real workout!” (more…)

The postmodernist critique of science consists of two interrelated arguments, epistemological and ideological. Both are based on subjectivity. First, because of the subjectivity of the human object, anthropology, according to the epistemological argument cannot be a science; and in any event the subjectivity of the human subject precludes the possibility of science discovering objective truth. Second, since objectivity is an illusion, science according to the ideological argument, subverts oppressed groups, females, ethnics, third-world peoples.

Well, it’s not really postmodernism per se that I detest. In the humanities, I don’t mind it so much, although reading postmodernist texts in college did make my head hurt. I suppose that in the humanities postmodernism provides a sometimes useful methodology for providing insights into interpretation of a wide variety of subjects in literature and the arts, although much of the time it seems to exist mainly to try to make texts mean exactly the opposite of what the words on the page say. Relying as it does on deconstruction, which is primarily a form of literary analysis, postmodern analysis is built on questioning the assumptions underlying any text, “deconstructing” its meaning. The problem is, it’s rare that a postmodernist critique of anything doesn’t consist of some of the densest, most impenetrable verbiage in existence.

Since I don’t claim to be a philosopher, and I haven’t studied postmodernism since college, I don’t intend to embarrass myself by trying to do a detailed–ahem–deconstruction of what postmodernism is. Many are the trees that have been killed to write books trying to explain what postmodernism is and how to apply it to various subjects. I do know, however, that postmodern philosphy is skeptical–even nihilistic–when it comes to the values of what is considered “modernity.” Unfortunately, to some, science is one of these modern values that is viewed with extreme skepticism, even to the point of representing the very essence of science as nothing more than one narrative among many. True, Spiro was writing primarily about anthropological science, but medicine is a “soft” enough science to be just as easily attacked in such a manner, and postmodernists don’t limit themselves to the “soft” sciences, anyway. Even worse, these sorts of arguments often claim that science (or, in this case, evidence-based medicine) is nothing more than a sort of hegemony of the power structure being imposed upon the very definition of “data” or “reality,” the implication that it’s us white males whose hegemony is being served (and whose hegemony, presumably, must be resisted) doing the imposing, as if there are no inherent characteristics in science that make it a more reliable means of assessing reality as it exists than, for example, personal anecdote and “experience.”

No wonder woo-meisters and those who hate the very concept of evidence-based medicine (as opposed to the deficiencies in how EBMranks evidence, which in fact were the reason why this blog is called Science-Based Medicine and not Evidence-based Medcine) love postmodernism so much. It’s the perfect tool for them to appeal to other ways of knowing and try to make it seem as though scientific medicine is no more valid a construct to describe reality than that of the shaman who invokes incantations and prayers to heal, the homeopath who postulates “healing mechanisms” that blatantly contradict everything we know about multiple areas of science, or reiki practitioners who think they can redirect “life energy” (or qi) for therapeutic effect. In the postmodernist realm all are equally valid, as there is no solid reason to make distinctions between these competing “narratives” and the “narrative” of scientific or evidence-based medicine.

Perhaps the best quick explanation of how postmodernism is used to attack science comes from Rob Helpy-Chalk:

Knowledge was always in some way relativized to culture, so that it was possible to talk about many “equally valid ways of knowing” of which enlightenment science was only one. For instance, contemporary biologists say that the cassowary (an ostrich-like creature) is a bird, albeit one that cannot fly. The Karam people of New Guinea, who live alongside the cassowary, say that the cassowary does not belong in the same category as the birds (which they call yakt) but bats do belong to that category. So who’s to say that the biologists are right and the Karam are wrong? Knowledge is all relative.

Claims to knowledge were also always in some way “constructed” or “socially constructed” in the postmodernist movements. This meant that they had less to do with grasping the way the world actually works and more to do with creating social structures that advanced the interests of the people who claimed to have knowledge. The science of thermodynamics was not really a description of the properties of heat. It was about convincing people to buy steam engines and arranging society so that they would be happy when they bought one.

Thus, one of the key tenets of some strains postmodernism is that knowledge is relative and “socially constructed,” usually for the purpose of reinforcing the existing power structure or furthering the interests of the “elite” who have the knowledge. It is therefore not surprising that critics of evidence-based and science-based medicine would find postmodernism to be a very attractive philosophical mantle in which to wrap their objections to the science that does not support their favored understanding of how disease works or what treatments are effective. After all, if all knowledge is relative, then why shouldn’t their way of knowing be just as valid as that of science, given that in the postmodernist view as used (or, as many philosophers would characterize it, abused) by “postmodernist” critics, science is just “another narrative.”(more…)

“If you’ve done six impossible things this morning, why not round it off with breakfast at Milliway’s—the Restaurant at the End of the Universe!”–Douglas Adams

I recently finished reading the book “The Joy of Pi” by David Blatner. There is a chapter about the concept of squaring a circle, also called the quadrature of a circle. The idea is that, with just a ruler and a compass, you construct a square of equal area to a given circle.

It turns out it cannot be done. It is, in this iteration of the multiverse, impossible. Not difficult, or implausible or really hard. Impossible. You cannot square a circle in a finite number of steps given the conditions of using only a ruler and a compass.

That it is impossible does not prevent people from trying. Individuals do derive solutions to squaring the circle, and sometimes the derivation is erroneous, and sometimes they have a solution that requires a new value for pi.

Pi is the ratio of the circumference of a circle to its diameter. Take the circumference of a circle, divide it by its diameter and get the endless, or transcendental, number 3.141592654….(1) That number is part of the fabric of this universe. It is a fundamental part of how life, the universe, and everything is put together (2). It is a curious psychopathology that some people feel that all of known mathematics is wrong, and that they have a solution to an impossible problem and that they have discovered the hither to unknown, one true value of pi as a result.

The Center for Disease Control (CDC) conducts an ongoing telephone survey of medical problems and health care utilization – called the National Health Interview Survey (NHIS). They recently released their data from 2007. This is the first year for which they specifically broke out questions assessing the use of so-called complementary and alternative medicine (CAM).

CAM is a political/ideological entity, not a scientific one. It is an artificial category created for the purpose of promoting a diverse set of dubious, untested, or fraudulent health practices. It is an excellent example of the (successful) use of language as a propaganda tool.

The fundamental intellectual flaw of “CAM” as a concept is that it is made to include modalities that are extremely diverse, even mutually contradictory, under one umbrella. Very deliberately modalities which are scientific and mainstream, like the proper use of nutrition, are often included under the CAM umbrella by proponents in order to make it seem like CAM is a bigger phenomenon than it actually is, and as a wedge to open the door for the more pseudoscientific modalities.

Kava is a plant that grows in the western Pacific. It was traditionally prepared as a drink and used for its psychoactive properties, including sedation, relaxation, and relief of anxiety. It is intoxicating but not addictive.

It has become a popular supplement in the US, used to treat anxiety, depression, insomnia, stress, and menopausal symptoms. It has also been suspected of killing quite a few people.

St. John’s wort, valerian, and omega-3 fatty acids have little therapeutic value for anxiety disorders, and their use should be discouraged.

But they recommended kava. Not only that, they gave it the highest quality-of-evidence rating: A. They said,

Short-term use of kava is recommended for patients with mild to moderate anxiety disorders who are not using alcohol or taking other medicines metabolized by the liver, but who wish to use “natural” remedies.

It was the best of times (for antivaccinationists). It was the worst of times (for antivaccinationists). It was the age of wisdom (definitely not for antivaccinationists). It was the age of foolishness (definitely for antivaccinationists). It was the epoch of belief (for antivaccinationists).

Such is the time we live in, my apologies to Charles Dickens, even though he is long dead.

Let’s face it. If we ignore the science, it is, alas, indeed the best of times for antivaccinationists. I’ve lamented the rise of non-science-based fearmongering among the antivaccine brigade before many times. Indeed, I’ve lamented how the influence of ignorant, unscientific dolts like Jenny McCarthy spouting nonsense about vaccines has already resulted in the resurgence of vaccine-preventable diseases such as measles in areas of the U.S. to the point where I’m not along in fearing that the bad old days will soon return, just as Andrew Wakefield’s litigation- and money-driven “studies” suggesting that the MMR was somehow responsible for autism and GI problems linked with autism resulted in the measles going from being conquered in the U.K. 14 years ago to being declared endemic again there, all because of the fear stoked in parents by bad science, paranoia, and anti-vaccine fearmongering.

Truly, it is the best of times for antivaccinationists, or so it seems from a superficial view.(more…)

Quacks and their apologists often cite surgery and emergency treatments of traumatic injury and a few other catastrophic or potentially catastrophic events as the only “conventional” or “allopathic” methods that they consistently recommend. Explicitly or implicitly, for most problems they tout “holistic” or “CAM” treatments. In modern medicine, however, there are plenty of non-surgical and non-emergency treatments whose outcomes are so manifest that even the most exuberant advocates of implausible medical claims (IMC) seem careful to steer clear, lest they blow their cover. Where are the promoters or consumers of homeopathic contraceptives? Why haven’t we heard of a chiropractic adjustment for high blood sugar? How many pitches for Ayurvedic treatments of gout have you seen? There are exceptions, of course, the most notable being the nearly ubiquitous anti-immunization stance among IMC promoters.

Anesthesiology and Implausible Claims

In my day job I specialize in anesthesiology, a non-surgical field whose methods are so obviously effective that little is heard from the IMC crowd. Consider: is it likely that even the slickest of the current crop of snake oil salesmen, if they had the bad sense to try, could talk many people into accepting an implausible method for rendering the body insensible to pain? No, that would require a more effective form of persuasion, such as that used in China to promote “acupuncture anesthesia” from the mid-1950s until the end of the Cultural Revolution in 1976. That’s a story I’ll tell another time.

A few other implausible claims have crept into the broader realm of anesthesiology. Stimulation of the “pericardial 6″ acupuncture point on the ventral aspect of the wrist is said to prevent post-operative nausea. There is little basis for this, the Cochrane Review notwithstanding. Verbal messages, given to a patient under general anesthesia, are said to result in “faster healing.” The major proponent of this claim is Peggy Huddleston, a self-described psychotherapist with an M.T.S. (Master of Theological Studies) degree from the Harvard Divinity School. Ms. Huddleston appears to have parlayed the “faster healing” claim into a successful entreprenurial venture, featuring a website, workshops, CDs, and a book:

Peer-review is a critical part of the functioning of the scientific community, of quality control, and the self corrective nature of science. But it is no panacea. It is helpful to understand what it is, and what it isn’t, its uses and abuses.

Overview

When the statement is made that research is “peer-reviewed” this is usually meant to refer to the fact that it has been published in a peer-reviewed journal. Different scientific disciplines have different mechanisms for determining which journals are legitimately peer-reviewed. In medicine the National Library of Medicine (NLM) has rules for peer-review and they decide on a case by case basis which journals get their stamp of approval. Such journals are then listed as peer-reviewed.

There was a full-page ad in my local paper today for Back in Action Spine and Health Centers, targeted at sufferers from almost any kind of chronic back pain. It started with “Are You Ready to Throw in the Towel and Just Live with Hurting So Bad?” It went on to make a number of claims:

Doctors can fix the problem.

Breakthrough medical technologies.

Treatments are FDA cleared.

Treatments are scientifically proven.

No side effects.

Best kept secrets for healing “bad backs.”

Corrects scoliosis.

Corrects compressed discs.

Several university studies at Johns Hopkins, Stanford and Duke have confirmed that these treatments work.

Their questionnaire can determine who will benefit – if you fit even one criterion like “does your back feel out of alignment?” or “do you have arthritis?” you should call right away.

The ad offers a “Free Qualifying Exam” but you “Must Not Wait” because appointments are limited and they can only honor this free offer for 3 weeks. To encourage you to call, they sweeten the pot with a FREE $49 gift bag.